eslint-plugin-regexp
Version:
ESLint plugin for finding RegExp mistakes and RegExp style guide violations.
189 lines (188 loc) • 8.25 kB
JavaScript
"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
const regexp_ast_analysis_1 = require("regexp-ast-analysis");
const utils_1 = require("../utils");
function getFlatElements(node) {
if (node.type === "ClassStringDisjunction") {
return node.alternatives;
}
if (node.type === "CharacterClass") {
const nested = [];
const addElement = (element) => {
if (element.type === "ClassStringDisjunction") {
nested.push(...element.alternatives);
}
else if (element.type === "CharacterClass") {
if (!element.negate) {
nested.push(...element.elements);
}
nested.push(element);
}
else {
nested.push(element);
}
};
node.elements.forEach(addElement);
return nested;
}
return [];
}
function removeDescendant(root, e) {
let { start, end } = e;
if (e.type === "StringAlternative") {
if (e.parent.alternatives.length === 1) {
e = e.parent;
start = e.start;
end = e.end;
}
else {
if (e.parent.alternatives.at(-1) === e) {
start--;
}
else {
end++;
}
}
}
const before = root.raw.slice(0, start - root.start);
const after = root.raw.slice(end - root.start);
return before + after;
}
exports.default = (0, utils_1.createRule)("no-useless-set-operand", {
meta: {
docs: {
description: "disallow unnecessary elements in expression character classes",
category: "Best Practices",
recommended: true,
},
schema: [],
messages: {
intersectionDisjoint: "'{{left}}' and '{{right}}' are disjoint, so the result of the intersection is always going to be the empty set.",
intersectionSubset: "'{{sub}}' is a subset of '{{super}}', so the result of the intersection is always going to be '{{sub}}'.",
intersectionRemove: "'{{expr}}' can be removed without changing the result of the intersection.",
subtractionDisjoint: "'{{left}}' and '{{right}}' are disjoint, so the subtraction doesn't do anything.",
subtractionSubset: "'{{left}}' is a subset of '{{right}}', so the result of the subtraction is always going to be the empty set.",
subtractionRemove: "'{{expr}}' can be removed without changing the result of the subtraction.",
},
fixable: "code",
type: "suggestion",
},
create(context) {
function createVisitor(regexpContext) {
const { node, flags, getRegexpLocation, fixReplaceNode } = regexpContext;
if (!flags.unicodeSets) {
return {};
}
function fixRemoveExpression(expr) {
if (expr.parent.type === "ExpressionCharacterClass") {
const cc = expr.parent;
return fixReplaceNode(cc, cc.negate ? "[^]" : "[]");
}
return fixReplaceNode(expr, "[]");
}
return {
onClassIntersectionEnter(iNode) {
const leftSet = (0, regexp_ast_analysis_1.toUnicodeSet)(iNode.left, flags);
const rightSet = (0, regexp_ast_analysis_1.toUnicodeSet)(iNode.right, flags);
if (leftSet.isDisjointWith(rightSet)) {
context.report({
node,
loc: getRegexpLocation(iNode),
messageId: "intersectionDisjoint",
data: {
left: iNode.left.raw,
right: iNode.right.raw,
},
fix: fixRemoveExpression(iNode),
});
return;
}
if (leftSet.isSubsetOf(rightSet)) {
context.report({
node,
loc: getRegexpLocation(iNode),
messageId: "intersectionSubset",
data: {
sub: iNode.left.raw,
super: iNode.right.raw,
},
fix: fixReplaceNode(iNode, iNode.left.raw),
});
return;
}
if (rightSet.isSubsetOf(leftSet)) {
context.report({
node,
loc: getRegexpLocation(iNode),
messageId: "intersectionSubset",
data: {
sub: iNode.right.raw,
super: iNode.left.raw,
},
fix: fixReplaceNode(iNode, iNode.right.raw),
});
return;
}
const toRemoveRight = getFlatElements(iNode.right).filter((e) => leftSet.isDisjointWith((0, regexp_ast_analysis_1.toUnicodeSet)(e, flags)));
const toRemoveLeft = getFlatElements(iNode.left).filter((e) => rightSet.isDisjointWith((0, regexp_ast_analysis_1.toUnicodeSet)(e, flags)));
for (const e of [...toRemoveRight, ...toRemoveLeft]) {
context.report({
node,
loc: getRegexpLocation(e),
messageId: "subtractionRemove",
data: {
expr: e.raw,
},
fix: fixReplaceNode(iNode, removeDescendant(iNode, e)),
});
}
},
onClassSubtractionEnter(sNode) {
const leftSet = (0, regexp_ast_analysis_1.toUnicodeSet)(sNode.left, flags);
const rightSet = (0, regexp_ast_analysis_1.toUnicodeSet)(sNode.right, flags);
if (leftSet.isDisjointWith(rightSet)) {
context.report({
node,
loc: getRegexpLocation(sNode),
messageId: "subtractionDisjoint",
data: {
left: sNode.left.raw,
right: sNode.right.raw,
},
fix: fixReplaceNode(sNode, sNode.left.raw),
});
return;
}
if (leftSet.isSubsetOf(rightSet)) {
context.report({
node,
loc: getRegexpLocation(sNode),
messageId: "subtractionSubset",
data: {
left: sNode.left.raw,
right: sNode.right.raw,
},
fix: fixRemoveExpression(sNode),
});
return;
}
const toRemove = getFlatElements(sNode.right).filter((e) => leftSet.isDisjointWith((0, regexp_ast_analysis_1.toUnicodeSet)(e, flags)));
for (const e of toRemove) {
context.report({
node,
loc: getRegexpLocation(e),
messageId: "subtractionRemove",
data: {
expr: e.raw,
},
fix: fixReplaceNode(sNode, removeDescendant(sNode, e)),
});
}
},
};
}
return (0, utils_1.defineRegexpVisitor)(context, {
createVisitor,
});
},
});